Officials in Mason County now say that no gun was found, and no one was arrested, following Tuesday’s lockdown at Illini Central High School.
The security clampdown was prompted by rumors that a student had brought a gun to school.
Students were kept in their classrooms for hours, and were searched as they finally left the building, but no weapon turned up.
Police had earlier said that a “person of interest” had been questioned, but now say no arrests were made.